Tire-pump.



W. U. WATSON.

TIRE PUMP.

APPLICATION FILED MAR-6,1917- 1,2,513. Patented Aug. 14, 191?.

r a citizen of the United States,

WILLIAM U. WATSON, OF CHICAGO, ILLINOIS.

TIRE-PUMP.

Specification of Letters Patent.

Patented Aug. 14L, 1917.

Application fi1ed March 6, 1917. Serial No. 152,583.

To all whom it may concern:

Be it known that I, WILLIAM U. WATSON, residing at Chicago, in thecounty of Cook and State of Illinois have invented a certain new anduseful. Improvement in Tire Pumps, of which the following is aspecification.

My invention relates to tire pumps, more particularly compound pumpsadapted to be operated by hand for forcing air into vehicle tires. Tirepumps have been made with a high and a low pressure cylinder side byside, but in the pumps heretofore constructed, the castings or fittingsfor the upper ends of the cylinders have required a good deal of toolingof one kind or another including boring, turning and threading. Theobject of my invention is to simplify the construction of the parts atthe upper end of the cylinders and dispense with a great portion of thetooling or machine work. The manner in which this is accomplished willbecome evident as the description proce'eds.

I accomplish my object by the construction shown in the accompanyingdrawings, in which:

Figure 1 is an assembly view from the side showing the complete pump,part of the central portion being broken away to render the view morecompact.

Fig. 2 is a side elevation, chiefly in section, on the line 2-2, Fig. 4.It shows the parts at the upper end of the cylinders.

- Fig. 3 is a side elevation, partly in section, on the line 3-3, Fig.4:.

Fig. 4 is a plan section on the line 44, F 1

Fig. 5 is a perspective view of the part which I shall term the plug,and

Fig. 6 is a perspective View of the part which may for convenience betermed the pump head.

Similar numerals refer to similar parts throughout the several views. 7

Referring to the accompanying drawings, the low pressure cylinder 1 andhigh pressure cylinder 2 are mounted side by side upon a base 3, whichis preferably of cast metal and broad enough to be bolted to the flooror to support the foot of the operator so that the pump may be heldstationary while being operated. The two cylinders are connectedtogether through the base by means of a sultable connecting aperture(not shown),

particularly with the .1 and 2. sure cylinder rod. By preference, lowpressure cylinder is notched to receive a lug 8 formed on the inside offlange 8.

Plunger rods 4 and 5 operate suitable plungers within the respectivecylinders, and these rods are operated by a handle 6. It will beunderstood that the plunger in the low pressure cylinder is soconstructed that the high pressure cylinder. On the down stroke,however, it will permit air to pass it to receive a new charge above itin the high pressure cylinder.

My present invention is concerned more pump head and plug which areshown separately in Figs. 5 and 6.

The pump head which I will denote in general by A, consists of a singlecasting of composite form. It has an annular flange 6 which fits overthe upper end of the low pressure cylinder as best shown in Figs.

It covers the top of the low presand seats thereon. It has a centralaperture 9 for accommodating the plunger rod l. The diameter of thisaperture is great enough to freely admit air into the cylinder duringthe down stroke of the plunger, but in the preferred construc tion thediameter of the aperture is not so great as to prevent the pump headfrom guiding, to a certain extent, the plunger the upper end of the Theupper end of the high pressure cylinder is approximately flush with theupper end of the low pressure cylinder, but at a point preferably aboutan inch below its upper end, the high pressure cylinder has an externalannular bead 10 formed in it. It will be understood that in thepreferred construction, both of the cylinders are made of steel tubingand this bead may be formed by a rolling process or any other methodknown in the art. Said bead forms a support or abutment for theoverlying portion ,of the pump head. The pump head has an integralbarrel 12 which descends to the upward in level of the bead 10 and therehas an inwardly projecting annular ledge 13 which overlies and issupported by said bead. It is good practice to interpose a washer 1ibetween the bead and the pump head, as best shown in Figs. 1, 2 and 3.The presence of the ledge 13 produces an annular well or chamber 16between the inside of the barrel 12 and the outside of the high pressure cylinder. This well alfords space for receiving the barrel 18 ofthe plug which is denoted in general by the reference letter B. Barrel18 is internally threaded so as to screw upon the externally threadedupper end of the high pressure cylinder. The plug is manipulated by anut 19 integral with it; and between the nut and the barrel there isformed a laterally extending annular flange 20 which, when the plug isscrewed down bears upon the upper surface of the pump head or upon awasher 21 overlying it. The plug is centrally apertured to accommodatethe plunger rod 5, and in order to prevent the escape of air, a stuflingnut 22 is screwed into the top of the plug surrounding the rod.

The pump has a passage 25 leading from the well 16 to a screws a hoseconnection 27. A port 28 is formed in the side of the high pressurecylinder for permitting the compressed air to flow from the highpressure cylinder to the passage 25 and thence out through the hoseconnection.

With my construction, the assembling of the parts is a very simplematter. After the two cylinders have been screwed or otherwise fastenedinto the base 3 the rods l, 5 with plungers detached are passed downthrough the head A and plug B and stuffing nut 22, after which theplungers are attached to the rods and then inserted into the respectivecylinders. The head A is then slipped down over the top of thecylinders. The barrel of the plug B is then dropped into the well 12 ofthe pump head. As soon as the barrel has reached the top of the highpressure cylinder, it is screwed down onto it until the annular flange20 bearing upon'the top of the pump head forces the pump head downfirmly onto the bead 10. The stufiing nut 22 is then applied in theordinary manner, after which the handle 6 is fastened in place and theassembly is complete.

It will be evident from the foregoing that when thus assembled the partswill be held very firmly together and leakage will be effectivelyprevented at the top of the high pressure cylinder. The pump head willbe adequately secured also to the top of a low pressure cylinder, but itis obvious that an air tight connection is not required at this point.Viewing the construction as a whole, it will be seen that as a result ofmy invention, the cylindersare held in proper relative positions, andare adequately closed and the tapped hole 26 into which two plunger rodsadequately guided by but two principal parts, viz: the pump head A andplug 13. This is very much simpler than any construction heretoforeaccomplished, and, as a result of this simplified construction andcombinative arrangement of parts which are usually made in separatepieces, I am able to dispense with a number of machining operations. Inthe first place, the configuration of the parts is so simple that,instead of machining them, they may with propriety be employed just asthey are cast-that is to upon what is commonly termed a foundry fit.Practically the only machine work required is the formation of the bead10 and the thread cutting on the outside of the high pressure cylinderand the inside of the barrel 18 of the plug.

Having thus described my invention, what I claim as new and desire tosecure-by Letters Patent, is: l

1. An air pump having two cylinders open at the uppenend, a pump headconfigurated to fit over the ends of both of said cylinders, one of saidcylinders having a projection formed at a point somewhat beneath itsupper end, said projection forming a seat for the pump head, and thepump head having a well surrounding the upper end of the last mentionedcylinder, and means screwing onto the threaded upper end of the lastmentioned cylinder and overlying the top of the pump head for holdingthe parts assembled.

2. An air pump having a high and a low pressure cylinder, a beadingformed somewhat below the delivery end of the high pressure cylinder, apump head fitting over the low pressure cylinder and having a wellencircling the end of the high pressure cylinder and seating upon saidbead, the end of the high pressure cylinder being threaded, and a plughaving a barrel dropping into said well and internally threaded to screwonto the end of the high pressure cylinder, said plug engaging the pumphead for holding it firmly seated. j

3. An air pump having a high and a low pressure cylinder arrangedupright, said cyllnders being connected at their lower ends and the lowpressure cylinder delivering into the lower end of the hig'hpre'ssurecyl nder, a pump head consisting of a single casting fitting over theupper ends of said cylinders, said pump head having an annular flangesurrounding the low pressure cylinder, and having a well surrounding theupper end of thehigh pressure cylinder, the high pressure cylinderhaving an annular projection somewhat below its upper end which forms aseat for the bottom of said well, the upper end of the high pressurecylinder being threaded, and a plughaving a barrel fitting loosely intosaid well and having an internal thread screwing onto the top of thesay, it is proper to rely high pressure cylinder, said plug having anannular flange overlying the top of the pump head for holding the partsassembled.

4. In an air pump, a high and a low pressure cylinder arrangedvertically, the lower end of the low pressure cylinder delivering to thelower end of the high pressure cylinder, a pump head consisting of asingle casting having a delivery hose connection and having an annularflange fitting over the top of the low pressure cylinder, an annularprojection on the high pressure cylinder somewhat beneath the upper endthereof, said pump head having a well surrounding and spaced from theupper end of the high pressure cylinder, and having an inwardlyprojecting annular ledge seating upon the annular projection on the highpressure cylinder, and a plug having a smooth, external, cylindricalsurface fitting into said well surrounding the upper end of the highpressure cylinder, said plug being internally chambered and internallythreaded to screw onto the threaded'upper end of the high pressurecylinder, and said plug having an annular flange overlying the pump headand engaging it for holding said ledge firmly seated upon the annularprojection on the high pressure cylinder.

In witness whereof, I have hereunto subscribed my name.

WILLIAM U. WATSON.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

